JSFiddle - React, Tailwind, and code Playground

HTML

<div id="sidebar">
    <img class="bg" src="http://i.imgur.com/yi8lGPu.png" />
    <ul id="sidenav">
        <li>	<a href="http://www.nerosdecoshoppe.com/collections/126546-custom-orders"><img src="http://i758.photobucket.com/albums/xx229/nerobasterdino/Text/menuFontPSDfile_zps07909da5.png" /></a>

        </li>
        <li>	<a href=""><img src="http://i758.photobucket.com/albums/xx229/nerobasterdino/Text/DesignSeries_zps3a1baebc.png" /></a>

        </li>
        <li>	<a href=""><img src="http://i758.photobucket.com/albums/xx229/nerobasterdino/Text/DecodenCases_zps369ccf66.png" /></a>

        </li>
        <li>	<a href="http://www.nerosdecoshoppe.com/collections/183038-nails"><img src="http://i758.photobucket.com/albums/xx229/nerobasterdino/Text/Nails_zpsc77c5d0e.png" /></a>

        </li>
        <li>	<a href="http://www.nerosdecoshoppe.com/collections/183036-necklaces"><img src="http://i758.photobucket.com/albums/xx229/nerobasterdino/Text/Necklaces_zps983a23c8.png" /></a>

        </li>
        <li>	<a href="http://www.nerosdecoshoppe.com/collections/258653-bracelets"><img src="http://i758.photobucket.com/albums/xx229/nerobasterdino/Text/Bracelets_zps9a4c3f9b.png" /></a>

        </li>
        <li>	<a href="http://www.nerosdecoshoppe.com/collections/126552-charms"><img src="http://i758.photobucket.com/albums/xx229/nerobasterdino/Text/Charms_zps7a802dc8.png" /></a>

        </li>
        <li>	<a href="http://www.nerosdecoshoppe.com/collections/126549-rings"><img src="http://i758.photobucket.com/albums/xx229/nerobasterdino/Text/Rings_zps46bcfc13.png" /></a>

        </li>
        <li>	<a href="http://www.nerosdecoshoppe.com/collections/126550-key-chains"><img src="http://i758.photobucket.com/albums/xx229/nerobasterdino/Text/KeyChains_zps9e30ffa2.png" /></a>

        </li>
        <li>	<a href="http://www.nerosdecoshoppe.com/collections/126551-hair-clips"><img src="http://i758.photobucket.com/albums/xx229/nerobasterdino/Text/HairClips_zpse1e4a75f.png" /></a>

  ...

CSS

#sidebar {
    width: 209px;
    position:relative;
}
#sidenav {
    list-style-type: none;
    position:relative;
    z-index:1;
}
#sidebar .bg {
    width:100%;
    height:100%;
    position:absolute;
    z-index:0;
}